In the optical lens making industry precision lenses, such as those used for prescription eyeglasses, are conventionally produced by grinding the lens to a rough finish using diamond grinders and thereafter polishing the lens to prescribed dimensions and a fine finish. In the polishing of such lenses conventionally a steel or hard plastic lapping block, which is sized and configured for the particular desired prescription, is placed in movable mating contact with the surface of the rough cut lens.
A grinding compound, which is mixed with water to form a slurry, is introduced between the surfaces of the lapping block and the lens, while one or both the block and the lens are moved in a figure eight motion. Additionally, it is conventional to polish a lens in a coarse manner using a relatively coarse grinding compound and thereafter producing a fine polished surface through the use of a grinding compound containing relatively fine particulate manner. During the polishing operation a pressure of approximately 30 pounds per square inch is applied to the lapping block. The above noted procedure is continued until the desired results of a highly polished, uniformly finished lens surface are obtained.
A disadvantage of the conventional lens polishing procedure is that there are approximately 2,000 different prescriptions, each requiring a different lapping block with each having a different radius of curvature. Thus, approximately 2,000 different lapping blocks would be required in order to obtain polishing of all the possible different prescriptions which may be required in the finished lens.